Enclosures for fluidic oscillators

ABSTRACT

For those spray applications that use a fluidic oscillator of the type that generates a spray by having a pressurized liquid flow through the oscillator and exhaust into a surrounding environment, and where such an oscillator has a boundary surface which has fabricated into it a channel in the form of what is referred to herein as fluidic circuit, an improved enclosure for this oscillator includes: a body having an interior and an exterior surface, wherein a portion of this interior surface is configured to attach to the oscillator boundary surface so as to form with the oscillator&#39;s channel an enclosed pathway through which the to-be-sprayed liquid may flow, and wherein a segment of this interior surface is configured so as to yield specified properties of the resulting spray.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of applicants' patentapplication U.S. Ser. No. 10/673,727, filed Sep. 29, 2003, and titled“Fluid Spray Apparatus,” which issued as U.S. Pat. No. 7,111,800 on Jul.12, 2005.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to fluid handling processes and apparatus. Moreparticularly, this invention relates to new methods and apparatus forenclosing fluidic oscillators or inserts so as to improve theirperformance.

2. Description of the Related Art

Fluidic inserts or oscillators are well known for their ability toprovide a wide range of distinctive liquid sprays. The distinctivenessof these sprays is due to the fact that they are characterized by beingoscillatory in nature, as compared to the relatively steady state flowsthat are emitted from standard spray nozzles.

FIG. 1 from U.S. Pat. No. 4,052,002 (Stouffer & Bray) demonstrates theoscillatory nature of the spray from a typical fluidic oscillator. Itshows what can be considered to be the essentially temporally varying,two-dimensional, planar flow pattern (i.e., in the x-y plane of theoscillator, and assuming that the width of the oscillator in thez-direction is large in comparison to its throat or outlet dimension) ofa liquid jet or spray that issues from the oscillator into a surroundinggaseous environment and breaks into droplets which are distributedtransversely (i.e., in the y-direction) to the jet's generallyx-direction of flow. Such spray patterns may be described by thedefinable characteristics of their droplets (e.g., the volume flow rateof the spray, the spray's area of coverage, the spatial distribution ofdroplets in planes perpendicular to the direction of flow of the sprayand at various distances in front of the oscillator's outlet, theaverage droplet velocities, the average size of the droplets, and thefrequency at which the droplets impact on an obstacle in the path of thespray).

A fluidic insert is generally thought of as a thin, rectangular memberthat is molded or fabricated from plastic and has anespecially-designed, uniform depth, liquid flow channel fabricated intoeither its broader top or bottom surface, and sometimes both (assumingthat this fluidic insert is of the standard type that is to be insertedinto the cavity of a housing whose inner walls are configured to form aliquid-tight seal around the insert and form an outside wall for theinsert's boundary surface/s which contain the especially designed flowchannels). See FIG. 2A. Pressurized liquid enters such an insert and issprayed from it.

Although it is more practical from a manufacturing standpoint toconstruct these inserts as thin rectangular members with flow channelsin their top or bottom surfaces, it should be recognized that they canbe constructed so that their liquid flow channels are placed practicallyanywhere (e.g., on a plane that passes though the member's center)within the member's body; in such instances the insert would have aclearly defined channel inlet and outlet. For example, see FIG. 2B fromU.S. Pat. No. 5,820,034 (Hess) which shows a two-part (50 a, 50 b),fluidic insert whose exterior surface is cylindrical so that this insertcan be fitted into a similarly shaped housing (72).

Additionally, it should be recognized that these flow channels need notbe of a uniform depth. For example, see U.S. Pat. No. 4,463,904 (Bray),U.S. Pat. No. 4,645,126 (Bray) and RE38,013 (Stouffer) for fluidicoscillators in which the bottom surfaces of these channels arediscretely and uniformly sloped so as to impact the ways in which thesprays from these oscillators spread as the move away from theoscillator's outlet.

There are many well known designs of fluidic circuits that are suitablefor use with such fluidic inserts. Many of these have some commonfeatures, including: (a) at least one power nozzle configured toaccelerate the movement of the liquid that flows under pressure throughthe insert, (b) an interaction chamber through which the liquid flowsand in which the flow phenomena is initiated that will eventually leadto the spray from the insert being of an oscillating nature, (c) anliquid inlet, (d) a pathway that connects the inlet and the powernozzle/s, and (e) an outlet or throat from which the liquid sprays fromthe insert.

Examples of fluidic circuits may be found in many patents, includingU.S. Pat. No. 3,185,166 (Horton & Bowles), U.S. Pat. No. 3,563,462(Bauer), U.S. Pat. No. 4,052,002 (Stouffer & Bray), U.S. Pat. No.4,151,955 (Stouffer), U.S. Pat. No. 4,157,161 (Bauer), U.S. Pat. No.4,231,519 (Stouffer), which was reissued as RE 33,158, U.S. Pat. No.4,508,267 (Stouffer), U.S. Pat. No. 5,035,361 (Stouffer), U.S. Pat. No.5,213,269 (Srinath), U.S. Pat. No. 5,971,301 (Stouffer), U.S. Pat. No.6,186,409 (Srinath) and U.S. Pat. No. 6,253,782 (Raghu).

Despite much prior art relating to the development of fluidic circuits,the nature of the housings or enclosures that surround fluidicoscillators have not changed much over the years. For example, FIG. 2Ashows a housing that was developed for automotive windshield washingapplications—one of the first areas in which such fluidic inserts wereextensively used. A fluidic oscillator is inserted into an especiallyconfigured cavity in the housing's front face. The overall shape of thehousing's exterior is aerodynamically configured from its rear to itsfront face in consideration of the fact that this housing will bemounted on an automobile's hood and in front of its windshield.

FIG. 3 from U.S. Pat. No. 6,062,491 (Hahn) shows a housing (1) that isnotable for its having two cavities into which cooperating fluidicoscillators are inserted.

FIGS. 4A and 4B from U.S. Patent Publication No. (USPPN) 2004-0227021show a housing (84) whose exterior surface has been especiallyconfigured to allow this housing and its enclosed fluidic oscillator tobe used as part of a “quick disconnect” nozzle assembly.

FIG. 5 from USPPN 2004-0164189, Ser. No. 10/673,727, shows a housing(42) which also has an exterior surface that has been especiallyconfigured to allow this housing to be used as part of a specializednozzle assembly (i.e., a showerhead). It also has a cavity that isespecially configured to accept a stack of fluidic oscillators (10) inwhich the centerlines of the adjoining oscillators have a specified,included angle of divergence.

While one generally thinks of the enclosures for these oscillators asbeing of an almost totally enclosing nature (in which case, we hereinrefer to them as housings), this need not be the case. FIG. 6 from U.S.Pat. No. 5,845,845 (Merke et al.) shows a “lid” (32) for enclosing onlythe boundary surface of the oscillator in which the fluidic circuit islocated.

As fluidic oscillators have continued to be used in more types ofapplications, the opportunity has arisen to re-examine and improve uponthe design of their enclosures as a way to improve upon the overallspraying performance of the nozzle assemblies, etc. which use fluidicoscillators.

3. Objects and Advantages

There has been summarized above, rather broadly, the prior art that isrelated to the present invention in order that the context of thepresent invention may be better understood and appreciated. In thisregard, it is instructive to also consider the objects and advantages ofthe present invention.

It is an object of the present invention to provide an assortment ofindividual housings or enclosures for fluidic oscillators that can behelpful in improving upon the actual spray performance of the spraydevices or nozzle assemblies that utilize fluidic oscillators.

It is an object of the present invention to provide fluidic sprayassemblies (i.e., fluidic oscillators with novel enclosures) that canprovide specific types of desired sprays that have heretofore not beenachievable with conventional fluidic technology. For example, touniformly cover a relatively large surface area (e.g., a 400 cm area ata distance of 30 cm from the spray head's exit) with liquid dropletsthat have large diameters (e.g., >2 mm), high velocities (e.g., > or ˜4m/sec) and possibly pulsating frequencies that are in the range ofperception by the human body (e.g., < or ˜30-60 hertz).

It is an object of the present invention to provide improved and moreversatile enclosures and fluidic spray assemblies that are ideallydesigned for shower head and body spray applications.

It is an object of the present invention to provide enclosures andfluidic spray assemblies that operate at low flow rates in shower headand body spray applications so as to yield significant water savings.

It is an object of the present invention to provide improved enclosuresand fluidic spray assemblies that are ideally designed for an assortmentof commercial cleaning applications.

It is an object of the present invention to provide enclosures andfluidic spray assemblies that can allow for reduced flow rates, whilestill yielding sprays that provide the same tactile sensations as theyimpact upon the skin of a user.

It is an object of the present invention to provide enclosures andfluidic spray assemblies that can allow for reduced energy consumption,while still yielding sprays that provide the same tactile sensations asthey impact upon the skin of a user.

It is an object of the present invention to provide enclosures andfluidic spray assemblies that can make “less water” feel like “morewater” (i.e., providing low flow rate sprays that provide the sametactile sensations as they impact upon the skin of a user).

It is an object of the present invention to provide enclosures andfluidic spray assemblies that prove to be ideally suited for showermassaging applications.

It is an object of the present invention to provide enclosures andfluidic spray assemblies that prove to be ideally suited for showernon-massaging applications.

It is an object of the present invention to provide enclosures andfluidic spray assemblies that allow a user to better direct and controlthe location of the areas being wetted by the sprays from suchassemblies.

These and other objects and advantages of the present invention willbecome readily apparent as the invention is better understood byreference to the accompanying summary, drawings and the detaileddescription that follows.

SUMMARY OF THE INVENTION

Recognizing the need for the development of improved enclosures andfluidic spray assemblies to more effectively and efficiently provide awider range of desired spray distributions, the present invention isgenerally directed to satisfying the needs set forth above andovercoming the disadvantages identified with prior art devices andmethods.

In accordance with the present invention, and for those sprayapplications that use a fluidic oscillator of the type that generates aspray by having a pressurized liquid flow through the oscillator andexhaust into a gaseous surrounding environment, and where such anoscillator has a boundary surface which has fabricated into it a channelin the form of what is referred to herein as fluidic circuit, apreferred embodiment of an improved enclosure for this oscillatorincludes: a body having an interior and an exterior surface, wherein aportion of this interior surface is configured to attach to theoscillator boundary surface so as to form with the oscillator's channelan enclosed pathway through which the to-be-sprayed liquid may flow, andwherein a segment of this interior surface is configured so as to yieldspecified properties of the resulting spray.

In a second preferred embodiment, the enclosure's body is configured asa housing with: (a) its exterior surface including an outer surface thatincludes a front and a rear face and an intermediate boundary surfacethat connects these faces, (b) its interior surface includes a passagethat extends between the faces, with this passage having a front and arear section, and wherein: (c) the rear section of this passage forms acavity having an opening in the body's rear face and is configured toallow for the insertion of the fluidic oscillator into the cavity, (d)the front section of this passage is configured so as to include thesegment that influences the properties of the resultant spray, and (e)this segment includes an element chosen from the group consisting of athroat, a throat expansion region, a second interaction region or anisland situated in the passage.

In a third preferred embodiment, the enclosure's body is configured as a“lid” with the portion of the interior surface having an upstream and adownstream end, and forming a surface that includes a plurality ofplanar parts, and wherein the planar part that is proximate itsdownstream end is sloped with regard to its adjoining upstream part soas to provide said interior surface with a slope angle that is in therange of 5 to 20 degrees.

Thus, there has been summarized above, rather broadly, the presentinvention in order that the detailed description that follows may bebetter understood and appreciated. There are, of course, additionalfeatures of the invention that will be described hereinafter and whichwill form the subject matter of the claims to this invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates the two-dimensional, planar spray flow patternyielded by an appropriately configured fluidic oscillator as disclosedin U.S. Pat. No. 4,151,955.

FIG. 2A illustrates the typical housing or enclosure for a fluidicoscillator that was developed for automotive windshield washingapplications.

FIG. 2B from U.S. Pat. No. 5,820,034 shows a two-part, fluidic insertwhose exterior surface is cylindrical so that it can be fitted into asimilarly shaped housing.

FIG. 3 from U.S. Pat. No. 6,062,491 shows a housing that is notable forits having two cavities into which cooperating fluidic oscillators areinserted.

FIGS. 4A and 4B from USPPN 2004-0227021 show a housing whose exteriorsurface has been especially configured to allow this housing and itsenclosed fluidic oscillator to be used as part of a “quick disconnect”nozzle assembly.

FIG. 5 from USPPN 2004-0164189 shows a housing which also has anexterior surface that has been especially configured to allow thishousing to be used as part of a specialized nozzle assembly (i.e., ashowerhead) having a cavity that accepts a stack of fluidic oscillatorsin which the centerlines of the adjoining oscillators have a specified,included angle of divergence.

FIG. 6 from U.S. Pat. No. 5,845,845 shows a “lid” for enclosing only theboundary surface of the oscillator in which the fluidic circuit islocated.

FIGS. 7A-7C show a perspective, top cross-sectional and sidecross-sectional view of a first preferred embodiment of the presentinvention.

FIG. 7D shows a perspective view of a preferred embodiment of thepresent invention in the form of an enclosure for use in a “body spray”assembly.

FIGS. 8A-8E show views of the front faces of various multi-cavityenclosures that illustrate additional embodiments of the presentinvention.

FIG. 9A shows a preferred embodiment of the present invention in theform of a housing that accommodates four fluidic oscillators.

FIG. 9B shows an exploded view of the showerhead that utilizes thefluidic assembly shown in FIG. 9A.

FIG. 9C shows a partial, downward-directed, cross-sectional view of thefluidic assembly shown in FIG. 4A.

FIG. 10 shows the front face of a showerhead embodiment of the presentinvention that has multiple modes of operation.

FIG. 11 illustrates the coordinate system which is being used herein todescribe the spray from a fluidic oscillator.

FIG. 12 illustrates a “lid” embodiment of the present invention beingused with a complimentary fluidic oscillator.

FIGS. 13A-13C show, respectively, a perspective, side and a sidecross-sectional view of another preferred “lid” embodiment of thepresent invention.

FIG. 14A shows a perspective view of a sectioned “interlocking lid”embodiment of the present invention.

FIG. 14B shows the embodiment of FIG. 14A after it has been turnedupside down so as to reveal the details of the lid's interior surface.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Before explaining at least one embodiment of the present invention indetail, it is to be understood that the invention is not limited in itsapplication to the details of construction and to the arrangements ofthe components set forth in the following description or illustrated inthe drawings. The invention is capable of other embodiments and of beingpracticed and carried out in various ways. Also, it is to be understoodthat the phraseology and terminology employed herein are for the purposeof description and should not be regarded as limiting.

A common problem encountered in developing and producing fluidicoscillators or inserts for use in automotive windshield applications isdesigning a fluidic circuit which can give the desired spraycharacteristics (e.g., at flow rates of 400 ml/minute and operatingpressures of 9 psig, uniform coverage with spray droplets of a targetarea located approximately 25 cm in front of the sprayer and having atarget area width of approximately 80 cm) and which can be fitted into ahousing which is very limited on its allowable size. Because suchhousings often are situated in locations on an automobile's hood thatare quite visible, their allowable dimensions are often dictated byaesthetic considerations (e.g., typical acceptable widths are on theorder of 10-12 mm). The consequence of this is that the spray from thewindshield washers situated in such housings must have, what is referredto as, a large horizontal fan angle, φ (i.e., as defined by thehorizontal boundaries of the region wetted by the spray, see FIG. 1).

Since such inserts and their enclosures are typically made by plasticinjection molding methods, those knowledgeable with such manufacturingmethods will understand that such manufacturing methods impose furtherconstraints on the geometry of such inserts and their enclosures. Forexample, a 12 mm wide housing can only accommodate a fluidic inserthaving a maximum width of about 9 mm since the wall thickness of suchhousings must typically be about 1 mm or larger.

In striving to improve the performance of various types of fluidicsprayers, we have discovered that there are significant opportunities tocreate and introduce new enclosures for these fluidic oscillators thatappreciably improve their performance.

FIGS. 7A-7C show, respectively, a perspective, a top cross-sectional anda side cross-sectional view of a first preferred embodiment of thepresent invention. In this instance, the novelty of the presentinvention is being illustrated with an enclosure 2 whose outer boundarysurface is generic in nature. This housing is seen to consist of a body10 that has an outer boundary surface 12 that includes a front 14 and arear 16 face and an intermediate boundary surface 18 that connects thesefaces. A passage or enclosed pathway 20 extends between these faces andhas been constructed to have a clearly defined front 22 and rear 24section or portion. The rear portion of this passage is configured toform a rectangular cavity 26 into which a rectangular-shaped fluidicoscillator 4 is to be inserted. The intersection of this cavity 26 withthe body's rear face 16 forms the opening 28 through which thisinsertion is accomplished.

It should be noted that this enclosure 2 is unique in that it allows forthe rear loading of a fluidic insert. This can be especially importantin various high pressure applications in which such frontally loadedinserts have been observed to be effectively spit from their housingsdue to excess pressure build-ups behind or upstream of the inserts.

The front portion 22 of this enclosure's passage is also unique in thatit is a segment 23 of the enclosure's interior surface that has beenconfigured so as to form another element of the to-be-insertedoscillator's fluidic circuit—both a throat 30 element and a throatexpansion region or element 32. Thus, the to-be-inserted fluidicoscillator that would be appropriate for use with this enclosure 2 wouldnot have such elements and its length would therefore be expected to beshorter than the usual similarly-operating fluidic oscillator.

FIG. 7D shows an example of such an enclosure 2 which has a non-genericouter boundary surface 12 and which allows for the rear loading of afluidic oscillator 4. In this example, the enclosure is for use in a“body spray” assembly which allows the enclosure's spherical shaped rearportion to be held in a spherical shaped cavity that allows one torotate the enclosure 2 so as to aim the direction of the jet of liquid 2that issues from its throat 30.

We have found that constructing fluidic oscillators and their enclosuresin this way can great simplify their fabrication and make it much easierto later modify them. We have also found that this arrangement allowsfor a broader range of geometries to be easily and convenientlyfabricated into these pieces. For example, we have been able tofabricate these enclosures so as to have larger expansion angles intheir throat expansion regions than could be fabricated into the top orbottom surface of the typical fluidic oscillator. The use of such largerangles has allowed us to produce oscillating sprays that have largerhorizontal liquid spreading or fan angles, φ, see FIG. 1

While this embodiment has shown only an enclosure with a front portion22 that includes the fluidic circuit elements of a throat 30 and throatexpansion region 32, it should be recognized that any of the other knownelements of such circuits could have also been included in this frontportion 22. For example, fluidic elements that could have been includedinclude an island (see U.S. Pat. No. 4,151,955), a second interactionregion (see U.S. Pat. No. 5,860,603), and a horizontal slot in thepassage's top or bottom surface (see U.S. Pat. No. 5,971,301). Otherpossible elements for inclusion are disclosed later in this section.

In working to further improve upon the design of such enclosures, it wasfurther discovered that these enclosure could be fabricated with manyespecially oriented and configured cavities in a single housing so as touse various unique arrays of fluidic oscillators to create a combinedspray whose droplet flow characteristics were unique in comparison tothose sprays that could be produced by any other known means.

For assorted showerhead applications, FIGS. 8A-8E show views of thefront faces 14 of various multi-cavity enclosures or housings 2 thatillustrate some of ways that it has been found to be beneficial toorient the outlets 34 for the fluidic-oscillator-holdingpassages/cavities contained in these enclosures. The frontal views ofthese enclosures also reveal that the perimeter of these housing frontfaces define circles, but it should be recognized that this is notimportant to the performance of such showerhead—what is important is theorientation and spacing between the enclosures' cavities.

FIGS. 8A-8D illustrate arrangements in which the outlets and theirrelated cavities are equally-spaced and arranged on the sides of avarious types of polygons (i.e., A—an octagon, B & C—a square, D—atriangle).

FIG. 8E illustrate an arrangement in which the outlets and their relatedcavities are equally-spaced and arranged on lines or spokes that spreadout from the face's center (i.e., shown here in a four spokearrangement, although other numbers of spokes could be used and shouldbe considered to fall within the scope of the present invention).

To demonstrate how the discoveries of the present invention can be usedto design a showerhead having a desired distribution of spray droplets,consider the following example. Suppose that it is desired to uniformlycover a surface area having dimensions of 35 cm×12 cm and which islocated at a distance of 30 cm in front of a showerhead. Further, assumethat the coverage is to be with droplets having a mean diameter ofapproximately 2 mm and an average velocity of approximately 4 m/sec.This is to be accomplished with a showerhead operating at 1.6 gpm atapproximately 10 psi and having four or fewer orifices so as to makethese orifices large enough to minimize the possibility that they willbecome clogged.

Until the teachings of the present invention, this task would have beenvirtually impossible since the known spray devices that could cover thetargeted area cannot do so uniformly with droplets of the desired sizeand velocity. However, we have discovered that the above requirementscan be met by utilizing a four-cavity enclosure similar to that whosefront face is similar to that shown in FIG. 8C and whose cavities aresized so as to accommodate fluidic oscillators that employ fluidiccircuits like those shown in U.S. Pat. No. 6,253,782.

FIG. 9A shows the body 10 of the actual enclosure 2 or housing used inthis application. The four fluidic oscillators 4A-4D that are insertedinto the openings in its rear face 16 are shown. The body's intermediateboundary surface is seen to be configured with a threaded region 36 soas to allow it to fit within and be mated to the surrounding parts(e.g., cosmetic front pieces 5A, 5B, a rear shell 6 piece, an adapter 7,a selector knob 8) that make up a complete showerhead. See FIG. 9B.

FIG. 9C shows a partial, downward-directed, cross-sectional view of thisfluidic assembly 3 (i.e., the enclosure 2 with one of its intendedfluidic oscillators 4 inserted). In this embodiment, the front portion22 of this body's passage is seen to have a throat expansion region 32molded into it.

The fluidic oscillators that have been chosen for this application areobserved to oscillate at a frequency of approximately 50 hertz and withthe wavelength of these oscillations being approximately 10 cm. Theresult is a large area spray that, to the human touch, has verypleasing, vigorous (because of the relatively high velocity and largediameter of the droplets) massaging qualities.

Furthermore, this spray is achieved at surprisingly low flow rates(i.e., ranges of 1.2-1.9 gpm versus non-fluidic, spray heads operatingin the range of 2.0-2.5 gpm) as compared to those used by the currentlyavailable, non-fluidic, massaging spray heads which cover significantlysmaller surface areas.

With a wide range of fluidic circuits from which to chose and with manyof these offering quite different flow characteristics, it would appearthat there exists an almost infinite number of especially designed spraydroplet distributions that can be achieved by utilizing enclosures orhousings that have multiple, strategically oriented cavities.

To provide maximum design flexibility in the design of a showerheadusing multiple fluidic oscillators, it should be recognized that theoscillators in these especially configured enclosures need not be all ofthe same kind. For example, oscillators with differing fan angles,oscillation frequencies, droplet sizes and velocities can be utilizedtogether to yield an almost infinite number of sprays. All of thesecombinations are considered to be within the teachings of the presentinvention.

Additionally, it can be noted that, using the teachings of the presentinvention, one can design a showerhead that has improved performancewith multiple modes of operation. FIG. 10 shows the front face 14 of amulti-cavity enclosure 2 that allows for the multiple mode operation ofany showerhead that uses such a fluidic assembly. The perimeter of thishousing 2 is seen to have a ring 38 of conventional orifices 40 thatemit a conventional, non-oscillating jet spray intended primarily forrinsing purposes. Within this ring there exists an octagonal array ofeight fluidic-oscillator-containing passages 20 i in which theoscillators that are inserted into these passages are also for rinsingpurposes. Proximate to and within this array and surrounding the centerof this face is a triangular array of threefluidic-oscillator-containing passages 20 j whose inserted oscillatorsare intended for massaging purposes. By judiciously choosing the natureof the fluidic oscillators that are inserted into these passages, onecan, as described below, improve the performance of such amulti-operating-mode showerhead.

Limited data suggests that most users of the conventionalmulti-operating-mode showerheads tend to keep their selector switchesturned to only a single mode of operation, even when these usersindicate that they would often prefer a mode of operation in which theywere using a combination of the multiple modes available with suchshowerheads (i.e., a combination of rinsing and massaging sprays). Thisis apparently the situation because such combined modes of operation arereported to suffer from the problem of the inadequate spray velocities.This is believed to be due to the massaging spray outlets robbing waterflow from the otherwise well performing rinse spray outlets. Bothfeatures perform well in their own right but when combined, both sprayssuffer performance degradation.

The showerhead which utilizes the new enclosure illustrated in FIG. 10is seen to overcome this problem of inadequate spray velocities. Atstandard operating pressures, the oscillators in the octagonal array ofpassages 20 i yield, for rinsing purposes, spray velocities of about 6m/sec in comparison to the orifices a conventional showerhead that yield3.5-5.2 m/sec. Alternatively, these oscillators can operate at 1.6 gpmto yield spray velocities that conventional showerheads can only yieldat flow rates of 2.5 gpm

Meanwhile, the oscillators in the triangular array 20 j yield, formassaging purposes, spray velocities of about 7.5 m/sec over an area ofgreater than 30 inches² as compared to the orifices of a conventionalshowerhead that yields 5.0-7.5 m/sec over an area of only about 5inches². In a combined mode of operation, the octagonal array ofpassages 20 i yield spray velocities of about 5 m/sec in comparison tothe orifices of a conventional showerhead that yield less than 2.5m/sec, while the triangular array 20 j yield spray velocities of about6.5 m/sec in comparison to the orifices of a conventional showerheadthat yields less than 5.5 m/sec.

In addition to investigating possible improvements that can be made tofluidic assemblies by changing what we have previously described as“enclosures of an almost totally enclosing nature (i.e., housings),” wehave also investigated the improvement that can be made in what we havepreviously referred to as the “lid” 42 for a fluidic oscillator 4. Wehave discovered that the rate at which the sprays emitted from suchlidded oscillators spread, widen or thicken in the plane that isperpendicular to their central axis of flow can be greatly influenced bytapering the lid's surface which is in contact with the oscillator andnear its outlet 4 a.

See FIG. 11 which shows the coordinate system which is being used hereinto describe such a spray (i.e., the centerline of the spray is in thex-direction and it exhibits both a spread in the x-y plane which isdefined by its horizontal fan angle, φ, and a vertical spread in the x-zplane which is defined by its vertical spread angle, θ, or its“thickness.”)

We have experimentally determined the degree that one can also use thesechanges in the lid's profile to cause the centerline of the spray to bedeflected upward or downward from the oscillator's aim or x-direction,which, as shown in FIG. 11, is perpendicular to the surface whichdefines the oscillator's outlet. The amount of this deflection can beconsidered to be defined in part by the vertical deflection angle γ thatexists between this deflected spray's centerline and the x-y plane.

FIG. 12 illustrates a further embodiment of the present invention in theform of a lid 42 which has a planar exterior surface 44 and aplanar-segmented interior surface 46. This interior surface gets itsname because it is the surface that is to be attached to theoscillator's boundary surface 4 b and which has fabricated into it thechannels 4 c through which the liquid flows through the oscillator. Theother well known parts of this fluidic circuit can also be seen in FIG.12: two power nozzles or means for inducing oscillations in the liquidthat flows through them, 4 d, an interaction chamber 4 e where the flowoscillations are created that cause the resulting spray to beoscillating in nature, a liquid inlet 4 f, a pathway 4 g that connectsthe inlet and the power nozzles, and a throat 4 h with its downstreamexpansion section 4 i.

The lid 42 is seen to have an upstream 48 and a downstream 50 end. Itspart or segment 52 which is proximate its downstream end is seen to besloped upward at an angle of β with regard to the plane defined by itsadjoining upstream part or segment 54.

This taper or slope to the downstream end of this lid enhances thespreading or thickening of the spray which issue from an oscillator 4that utilizes such a lid 42. To emphasize this point, we call this typeof combination a “thickening” lid-oscillator combination. For a β=9degree taper in the lid and a similar 9 degree taper in oscillator'sboundary surface proximate its downstream end, it was found the sprayfrom this oscillator could be caused to thicken much faster than onefrom a similar oscillator that had only the traditional, flat bottomedlid: the spray's vertical spread angle, θ, was approximately 9 degreesas compared to the 1-2 degrees of spread that was observed on the sprayfrom the oscillator that utilized the flat-bottomed lid. Lid tapers orslopes in the range of 2-15 degrees have proved effective in greatlyincreasing the downstream rate at which the spray from a wide assortmentof fluidic oscillators spread or thicken.

From our experiments with such modified lids, we also found that it waspossible to deflect such sprays while causing little change in theirrates of thickening. FIGS. 13A-13C show, respectively, a perspective,side and a side cross-sectional view of a preferred embodiment of thepresent invention. To distinguish the FIG. 13 embodiment from that shownin FIG. 12, we call the FIG. 13 combination a “deflection”lid-oscillator combination.

This “deflection” lid-oscillator combination differs from the“thickening” lid-oscillator combination shown in FIG. 12 because thedownstream portion of the floor 4 j of the FIG. 13 oscillator's channelbeneath the tapered portion of its lid 42 is given this same taper(e.g., β). As shown in FIG. 13C, this configuration provides the channelof the “deflection” lid-oscillator combination with a uniform depth(which was noted in the third paragraph of the section “Description ofRelated Art” as being the usual configuration for a fluidic insert oroscillator).

From the above noted difference, it directly follows that the downstreamportion of the channel floor of the “thickening” lid-oscillatorcombination of FIG. 12 does not have a taper β applied to its channelfloor. Furthermore, it also follows that, when the downstream portion ofthis combination's oscillator's boundary surface turns upward to matchthe lid's taper while its underlying channel floor has no such appliedtaper, the depth of this downstream, underneath this tapered lid portionof oscillator's channel actually increases in magnitude (in contrast tothe uniform depth channel shown in FIG. 13C).

The FIG. 13 “deflection” lid-oscillator combination of tapers has beenfound to yield sprays whose deflection angles γ are approximatelyequivalent to the imposed taper angles β for angles in the range of 5 to30 degrees. Taper angles β in the range of 2 to 45 degrees have beenexperimentally examined and found to be effective in controlling aspray's lateral spread. The use of such taper angles are considered tocome within the scope of the present invention.

It should also be noted that such a nozzle could also be incorporatedinto the front portion of the housing shown in FIG. 7. Additionally, itshould be noted that, if the oscillator's floor 4 j were to have a taperless than that of the lid so that the depth of the oscillator's channelin this downstream portion were to be effectively increasing inmagnitude in its downstream direction, the effect would be to increasethe rate at which the spray thickens as it spreads downstream.Conversely, if the oscillator's floor 4 j were to have a taper that isgreater than that of the lid so that the depth of the oscillator'schannel were to be effectively decreasing in magnitude in its downstreamdirection, the effect would be to decrease the rate at which the spraythickens as it spreads downstream. These embodiments could be referredto as, respectively, a “deflection and thickening combinations” or a“deflection and thickness-decreasing combinations.”

While the above discussion is in terms of a lid having planar sectionsthat therefore provide for an abrupt change in the lid's profile, itshould be recognized that this need not be the case as the lid can bemolded so as to have sections with smooth curves or curvature. Suchembodiments are considered to fall within the disclosure of the presentinvention.

FIGS. 14A-14B show a perspective view of one side of a sectioned lid andoscillator that comprise another preferred embodiment of the presentinvention. FIG. 14B shows the elements of FIG. 14A after they have beenrotated 180 degrees or turned upside down so that the details of thelid's interior surface are better seen.

This embodiment has been developed to provide a better means for sealingsuch lids to their appropriate oscillators. We refer to this assembly asbeing “interlockable” or “interlocking.” It consists of a lid 42 whoseinterior surface is further contoured so as to have an elevated portion56 that has a perimeter with a lid boundary edge 58 and an adjoining lidwall 60. This portion may also have cavities or protrusions that matewith correspondingly-shaped protrusions or cavities that are built intoa fluidic oscillator's channeled boundary surface.

The oscillator's channel has a floor 4 j and a wall 4 k that extendsfrom the floor and ends in at the channel's upper boundary edge 4 l.These boundary edges 58, 4 l are configured so as to allow at least aportion of the lid wall 60 to nest or interlock within the channel wall4 k so as to provide adjoining wall surfaces that can be used to createa liquid tight seal for the flow pathway that these elements create whenthey are interlocked. With this interlocking feature, it is no longernecessary to have such a precise fit between the outer surfaces of theseelements and the interior surfaces of the cavity of any primary housinginto which such a combination might be inserted so as to lock or orientthis combination into its position of use.

In this embodiment, a barrier 4 m in the oscillator's channel serves toform a power nozzle at each of its ends. This height of this barrier isgreater than that of the filter posts 4 n that are just upstream of it.Meanwhile, the lid's interior surface 46 is seen to have abarrier-accommodating cavity which accepts this barrier's additionalheight. In general, the portion of this lid's interior surface that sitsright above the oscillator's channels has been made thicker than iscustomary, except for the barrier-accommodating cavity, so that it canproject down into the oscillator's cavity so as to create, at thisportion's or protrusion's edges, vertical extending surfaces along whichthe oscillator's flow channel can be sealed.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and changes willreadily occur to those skilled in the art, and because of the wideextent of the teachings disclosed herein, the foregoing disclosureshould not be considered to limit the invention to the exactconstruction and operation shown and described herein. Accordingly, allsuitable modifications and equivalents of the present disclosure may beresorted to and still considered to fall within the scope of theinvention as hereinafter set forth in the claims.

1. A fluidic lid-oscillator combination that operates on a pressurizedliquid flowing through said combination to generate an oscillating sprayof liquid droplets into a surrounding gaseous environment, saidcombination comprising: a fluidic oscillator having a boundary surfacethat has fabricated therein a flow channel with upstream and downstreamends, a specified depth and a means for inducing oscillations in saidliquid that flows through said channel, a lid having an interior and anexterior surface, with said interior surface configured to attach tosaid oscillator boundary surface so as to form with said channel anenclosed pathway through which said liquid flows, wherein said lidinterior surface having upstream and downstream ends, wherein a portionof said lid interior surface that is proximate said downstream end beingsloped at a herein defined lid slope angle, β, with regard to said lidinterior surface portion that is proximate said upstream end, andwherein the depth of the downstream portion of said oscillator channelthat is beneath said tapered lid interior surface increasing inmagnitude, relative to the depth of the upstream portion of saidchannel, in said channel's downstream direction.
 2. The combination asrecited in claim 1, wherein said lid slope angle, β, is in the range of2 to 45 degrees.
 3. A method of making a fluidic lid-oscillatorcombination that operates on a pressurized liquid flowing through saidcombination to generate an oscillating spray of liquid droplets into asurrounding gaseous environment, said method comprising the steps of:forming a fluidic oscillator having a boundary surface that hasfabricated therein a flow channel with upstream and downstream ends, aspecified depth and a means for inducing oscillations in said liquidthat flows through said channel, forming a lid having an interior and anexterior surface, with said interior surface configured to attach tosaid oscillator boundary surface so as to form with said channel anenclosed pathway through which said liquid flows, wherein said lidinterior surface having upstream and downstream ends, wherein a portionof said lid interior surface that is proximate said downstream end beingsloped at a herein defined lid slope angle, β, with regard to said lidinterior surface portion that is proximate said upstream end, andwherein the depth of the downstream portion of said oscillator channelthat is beneath said tapered lid interior surface increasing inmagnitude, relative to the depth of the upstream portion of saidchannel, in said channel's downstream direction.
 4. The method asrecited in claim 3, wherein said lid slope angle, β, is in the range of2 to 45 degrees.